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DescriptionThis adventive annual vine is up to 3' long. It branches frequently at the base and less often elsewhere. The slender stems are light green to reddish green and hairless. They have the capacity to twine about the stems of adjacent plants and the wire of fences. The alternate leaves are widely spaced along the stems and have long slender petioles. They are up to 2½" long and 1" across, cordate or sagittate, smooth along the margins, and hairless. Their texture is rather thin and delicate. At the base of each petiole is a membranous sheath (ocrea) that wraps around the stem. This sheath is rather short and hairless. Individual or pairs of flowers develop from the axils of the upper leaves on short slender petioles. Short terminal racemes of flowers about 1-2" long also develop from some of the upper stems. These flowers are about ¼" long and have 3-5 petal-like sepals that are greenish white, white, or light pink. Each sepal is slightly keeled along its outer surface. Each flower matures into a 3-angled achene that is oblong, but widest in the middle. It is only slightly winged or keeled. The flowers develop and mature rather quickly on young stems where new growth occurs. The blooming period occurs during the summer and lasts 2-3 months. Each fertile flower is replaced by a large black achene that is 3-sided; the surface of this achene is dull along the sides, but shiny along the angles. The root system consists of a slender branching taproot. This plant spreads by reseeding itself.